1. Field of the Invention
This invention pertains to the general field of rapidly drying coatings for lacquers and enamels applied to human nails. In particular, the invention concerns a new composition and method for its application which provide a smooth, hard and glossy coating that cures in minutes and is easily removable by commercial nail polish removers.
2. Background of the Invention
Nail polish, lacquers and enamels comprise a class of products regularly used by modern women as part of their beauty care regimen. Enamels are available in a multitude of colors and it is not uncommon for women to strip and reapply nail enamels several times a week in order to match their wardrobe and makeup. This process is time consuming because three to four different layers of coating must be applied and allowed to air dry. Typically, a first layer of colorless base coat is applied, then two layers of color enamel and, finally, a layer of colorless enamel for gloss and protection. During the drying period, which can take as long as several hours, women have to refrain from tasks that might cause them to mar this painstakingly, and sometimes expensively, applied nail polish. Simple operations, such as opening a car door or extracting keys from a purse, can quickly ruin freshly applied fingernail enamel. Thus, in effect, they are prevented from using their hands in any normal everyday activity while the polish is drying. This is especially burdensome for salon customers who need to be able to function normally immediately after receiving a manicure.
Realizing the burden that air drying methods put on people with freshly manicured hands, devices have been developed to try and expedite the drying process. See, for example, U.S. Pat. No. 2,262,274 to Fingerlin (1941) and U.S. Pat. No. 2,374,472 to Corbett (1945). These devices consist generally of a box-like dryer that blows or circulates hot or cold air on the nail's surface for a specified period of time. However, these devices can only dry the surface of the top coating on the nail and do not cause any drying underneath. Consequently, additional exposure to air is required to dry the lower coats of nail polish and in the meantime a manicure can be easily ruined if the nail's surface comes into contact with any hard surface. As a result, nail polish wearers still have to use their hands cautiously for several hours after application in order not to ruin the product of a manicure.
U.S. Pat. No. 3,896,014 and U.S. Pat. No. 3,928,113 to Rosenberg (1975) disclose a process for coating nails comprising the steps of applying a water soluble base coat to the nails, allowing the base coat to dry, then applying a photocurable nail lacquer and curing the lacquer by exposing it to sufficient amounts of radiation. The inventive purpose behind this patent was to try to develop a nail coating that could be removed by water instead of an acetone based commercially available nail polish remover. Accordingly, the nail lacquer was specifically designed for a water soluble base coat, and commercially available nail polishes could not be used in the process. The water soluble base coat that rendered the photocured composition strippable also made the cured film incompatible with daily human functions such as hand and dish washing, bathing, and all other activities involving the immersion of nails in water.
U.S. Pat. No. 4,596,260 to Giuliano (1986) discloses a process of applying a photocurable coating to an artificial nail tip whereby upon exposure to suitable radiation the coating hardens to give the appearance of a natural nail. As it consists of a polyfunctional polymer to which the monomer is crosslinkable, the photocurable coating is very difficult to remove if applied to commonly used nail polishes.
Thus, while these references are relevant to show the general state of the art, they are not directed to the inventive purpose behind the subject invention, which is to rapidly dry a protective coat that can be applied on any commercially available nail polish, lacquer and enamel. Several commercial products have already been introduced that promise a reduction of the drying time of nail coatings. These products include silicone and mineral oils, which provide a slippery surface to the enamel and thus render it non-tacky; but they leave the solvents in place and do not harden the enamel. Also employed are cyclic siloxanes and other low boiling liquids that dry the top surface of the enamel as they evaporate with some of the solvents near the surface. The problem here is that the bulk of the multilayer enamel coating is left laden with solvent and still takes hours to dry and harden.
Infrared lamps, which aid the volatilization of the solvents in the enamel by increasing its temperature, reduce the drying time to about 30 minutes. This is still unsatisfactory, though, for today's growing number of working women who have to juggle their time between a job and housework.
Thus, a method that will further reduce the drying time of multilayer enamel coatings is still needed and it could be expected to have great commercial value in the cosmetics industry. The ultraviolet light apparatus and method described in the copending application referenced above are directed to this specific need.